feat: screenshot API, camera control, pipe/wire crossing detection

New endpoints:
- POST /api/action/screenshot: capture screenshot to file
- GET /api/screenshot/latest: serve PNG binary
- POST /api/action/camera: move camera to (x,y) + set zoom
- GET /api/state/camera: get current camera position/zoom

Pipe/Wire crossing intelligence:
- build_pipe/build_wire now detect existing pipes/wires at each cell
- mode='line' (default): new pipe merges with existing
- mode='cross': auto-places bridges at intersections to avoid connection
- mode='single': one segment

CLI: snapshot [file.png], camera <x> <y> [zoom], camera_status
All high-level commands: auto pause, execute, resume

tools/oni_commander.py

@@ -141,13 +141,14 @@ def cmd_fix_overload(args):
 
 
 def cmd_build_pipe_line(args):
-    """铺设管道路径。"""
+    """铺设管道路径（带交叉模式）。"""
     if len(args) < 5:
-        print("Usage: build_pipe_line gas|liquid <x1> <y1> <x2> <y2> [bridge]")
+        print("Usage: build_pipe_line gas|liquid <x1> <y1> <x2> <y2> [mode]")
+        print("  mode: 'line'(默认,与已有管线合并) | 'cross'(跨接器跳过) | 'single'(单段)")
         return
     ptype = args[0]
     x1, y1, x2, y2 = int(args[1]), int(args[2]), int(args[3]), int(args[4])
-    bridge = len(args) > 5 and args[5] == 'bridge'
+    mode = args[5] if len(args) > 5 else 'line'
 
     pause_before()
 
@@ -157,11 +158,15 @@ def cmd_build_pipe_line(args):
 
     result = api_post('/api/action/build_pipe', {
         "type": ptype, "x1": x1, "y1": y1,
-        "x2": x2, "y2": y2, "bridge": bridge
+        "x2": x2, "y2": y2, "mode": mode
     })
     if result.get('success'):
-        segs = result.get('data', {}).get('segmentCount', 0)
+        d = result.get('data', {})
+        segs = d.get('segmentCount', 0)
+        bridges = d.get('bridgesPlaced', 0)
         print(f"[OK] {ptype} pipe: {segs} segments from ({x1},{y1}) to ({x2},{y2})")
+        if bridges > 0:
+            print(f"  {bridges} bridges placed at crossings (mode={mode})")
     else:
         print(f"[!] Failed: {result.get('errorMessage', 'unknown')}")
 
@@ -295,8 +300,20 @@ COMMANDS = {
     'emergency_o2': cmd_emergency_o2,
     'build_pipe_line': cmd_build_pipe_line,
     'build_wire_line': cmd_build_wire_line,
+    'snapshot': cmd_snapshot,
+    'camera': cmd_camera,
 }
 
+def cmd_snapshot(args):
+    """Take screenshot + view. Usage: snapshot [name]"""
+    from oni_api import cmd_snapshot as api_snapshot
+    api_snapshot(args)
+
+def cmd_camera(args):
+    """Move camera. Usage: camera <x> <y> [zoom]"""
+    from oni_api import cmd_camera as api_camera
+    api_camera(args)
+
 if __name__ == '__main__':
     cmd = sys.argv[1] if len(sys.argv) > 1 else 'help'
 
@@ -316,11 +333,15 @@ if __name__ == '__main__':
         print("  expand_base <x> <y> <w> <h> 挖掘+建造墙壁（一键拓展房间）")
         print()
         print("=== Pipe / Wire Lines ===")
-        print("  build_pipe_line <t> <x1> <y1> <x2> <y2> [bridge]")
-        print("    t: gas | liquid")
-        print("  build_wire_line <t> <x1> <y1> <x2> <y2> [bridge]")
+        print("  build_pipe_line <t> <x1> <y1> <x2> <y2> [mode]")
+        print("    t: gas | liquid | mode: line(merge) | cross(bridge)")
+        print("  build_wire_line <t> <x1> <y1> <x2> <y2> [mode]")
         print("    t: regular | heavy | conductive | heavy_conductive")
         print()
+        print("=== Screenshot / Camera ===")
+        print("  snapshot [file.png]       Take screenshot")
+        print("  camera <x> <y> [zoom]     Move camera view")
+        print()
         print("All high-level commands auto-pause/resume the game.")
     else:
         COMMANDS[cmd](sys.argv[2:])